Answer:
it's 
Step-by-step explanation:
Answer:
I believe it would be (c)
Given that the number of bridges has been modeled by the function:
<span>y=149(x+1.5)^2+489,505
To find the year in which, y=505000 we shall proceed as follows:
From:
</span>y=149(x+1.5)^2+489,505
substituting y=505000 we shall have:
505000=149(x+1.5)^2+489,505
simplifying the above we get:
0=149(x+1.5)^2-15495
expanding the above we get:
0=149x^2+447x+335.25-15495
simplifying
0=149x^2+447x-15159.8
solving the quadratic equation by quadratic formula we get:
x~8.69771 or x~-11.6977
hence we take positve number:
x~8.69771~8.7 years~9 years
thus the year in which the number will be 505000 will be:
2000+9=2009
2y + 2x = 6
2y - x = 12
Subtract
3x = -6, x = -2
2(-2) + 2y = 6
-4 + 2y = 6
2y = 10, y = 5
Final solution: x = -2, y = 5
Answer:
Step-by-step explanation:
3tasks=7/10 hours
1 task=7/(10×3)
1 task=7/30 hours
Hence a robot takes 7/30 hours to complete one task
